[Immunodiagnosis of HIV infection in the transfusion service].
Enzyme immunoassay (EIA) is the basic method of the laboratory diagnosis of HIV-infection used as the first component of donors' screening. The possibility of nonspecific reactions presents a significant shortcoming of this method. An algorithm involving three stages has been elaborated to investigate donors for anti-HIV antibodies and to verify seropositive samples. The first-stage screening is conducted with the use of Soviet test-reagents. Positive samples are assayed again in the Soviet EI-systems based on varying types of sorbed antigens. In case of questionable or positive reactions the sample is assayed in commercial imported test-systems (the second stage). The positive sera are assayed in the immunoblotting test (the third stage). The algorithm suggested provides a reliable control and is worthwhile economically. The causes of nonspecific reactions in EIA have been described.